Barack Obama is setting the stage for his upcoming visit to Iraq with a high-profile explanation of his opposition to the war there and his pledge to complete a U.S. troop pullout within 16 months of becoming president.

John McCain gives the impression of a man running not for president but for commander in chief. He seems more animated by national security concerns than by the drudgery of domestic issues, even though the country's economic woes are likely to be the central issue in this fall's presidential election.

Barack Obama mourned the death of nine U.S. soldiers in Afghanistan on Sunday, even as he said John McCain's numerous visits to the region don't leave the Republican better equipped to deal with its volatility as president.

Preparing to embark on only his second visit to Iraq, as well as his first to Afghanistan, the Democrat told reporters: "I will recall the visit he made last year in which he was surrounded by helicopters and SWAT teams and he came back and reported how safe everything was in Baghdad. And I don't think that that was indicative of what was actually happening on the ground at that time."

So how old is John McCain? Six-packs, automatic transmissions and the American Express card were all introduced after he was born, not to mention computers which McCain admits he doesn't use.

McCain, himself, jokes that he's older than dirt. And while his age is being raised as a campaign issue, medical experts say voters shouldn't be concerned that, if elected, McCain would be the oldest man to assume the presidency, at 72.

Comedian Bernie Mac endured some heckling and a campaign rebuke during a surprise appearance Friday night at a fundraiser for Democratic presidential candidate Barack Obama.

Toward the end of a 10-minute standup routine at the Hyatt Regency Hotel in downtown Chicago, the 50-year-old star of "The Bernie Mac Show" joked about menopause, sexual infidelity and promiscuity, and used occasional crude language.

In recent weeks, the presumptive Democratic nominee has backed away from his opposition to a wiretapping law that would grant telephone companies de facto immunity for their participation in warrantless wiretapping after 9/11. He backed away from his pledge to stay within public-financing limits during the general election campaign. And he has recently signaled a willingness to shift ground on his plans to withdraw American troops from Iraq.

Some conservatives claim Obama is moving to the center to disguise his liberal leanings. And liberal bloggers are threatening to withdraw their support.